The good news is that your load will take a whitetail as-is. Velocity is about the same as the load I used in a 10 bore pistol, and that load shot through a 200# corn-fed mule deer at 25 yards. But I think increasing the velocity will result in smaller groups and lower the POI. If you are still 7" high at 25 yards, the shots aren't matching the sights yet.

At least one of your patches is torn; thicker patching might help (if it isn't so tight you can't load). How was the fouling?

The felt wad may be an issue. Unless there is a need to move the ball out past breech corrosion, I don't use a thick wad as I've not had good luck with them. Even then it is a trade-off: is the gun more-accurate with the wad or with patches torn by the corroded area?

In the smoothbores, I do usually use a wad, but only an overshot wad or a split (in thickness) .125" nitro wad seated on the powder. In those cases (I think) the wad serves to protect the patches: groups aren't smaller with a wad, but they are more consistent.

Some group sizes for comparison:
-a smoothbore 4 bore "wall gun" gave 5 shot groups of <9" at 200 yards (all shots stayed on a 9" paper plate)
-a 6 bore rifle (also 1:48 ROT, as that was the rifling in the barrel I used as a guide) gave 5 shot groups of about 3" at 100 yards
-a smoothbore 6 bore gave 5 shot groups of about 6" at 100 yards
-a rifled .78 caliber flintlock target rifle gave 5 shot 100 yard groups of 2"

Velocities on these loads were all >1,400 fps. The 6 bore and the flintlock target rifle were probably more accurate than the groups reflect: I'd hit the limits of my recoil tolerance.